Many vehicles include a security system, remote keyless entry system, and/or remote start system which permit a user to perform a function when away from the vehicle. For example, the security system may be switched between armed and disarmed modes by operation of a small handheld remote transmitter. Similarly, remote keyless entry and remote engine starting features can be similarly performed using a suitable remote transmitter. Typically such transmitters are dedicated and sold as part of the overall remote control system. Such systems can be factory installed or added as aftermarket accessories.
A remote start system may also provide a relatively convenient way for a vehicle user to control an operating temperature of a vehicle, for example, to a desired temperature, by remotely starting the engine. Once the engine has been started, the vehicle's climate control system (i.e., heating and cooling systems) may moderate the vehicle cabin temperature to a preset temperature that is comfortable to the user.
Additionally, remote start system may provide a more convenient way for a user to also raise the engine operating temperature and engine component temperatures, such as oil and other engine fluids, for example, in preparation of vehicle movement. This may be particularly advantageous in cold environmental conditions.
However, in some remote start situations the engine of the vehicle may be permitted to idle despite the desired engine and cabin temperatures having been reached. At this point fuel is unnecessarily consumed and excess pollution is generated.
Several references disclose stopping an engine of a vehicle after a threshold time period. More particularly, U.S. Pat. No. 4,381,042 to Perry discloses starting a timer if either an emergency brake switch or seat switch closes while the engine is operating. If the timer expires before either the emergency brake switch or seat switch opens, the engine is stopped.
U.S. Pat. No. 5,219,413 discloses stopping an engine when an engine is left idling unattended for a threshold time period. The vehicle is determined to be unattended via a motion detector. Temperature sensors may be used to determine whether the vehicle is moving prior to stopping the engine.
U.S. Pat. No. 7,310,576 to Letang discloses stopping a vehicle engine when an idle time threshold is exceeded. The idle time threshold is set based upon a geographical location of the vehicle.
Further improvements to remote start systems with respect to idle time may be desired. More particularly, it may be desirable to more efficiently control idle time thresholds in a remote start system, for example, to improve fuel efficiency and comply with environmental policies.